🛠 Démarrer le module radio et rejoindre un réseau LoRaWAN

Objectives

This tutorial replaces the classic "Wi-Fi scan": the board has no Wi-Fi module (no ESP32/NINA). The confirmed hardware equivalent is the Murata CMWX1ZZABZ LoRa radio module, a second CPU (STM32L0) that drives the SX1272 transceiver and communicates via AT commands over SPI. We start the module, read its identifier, and then join a LoRaWAN network using OTAA (The Things Network or a private server).

Hardware

• 1 Arduino MKR WAN 1300 + micro-UFL antenna (EU868 or US915 band depending on the version)
• The Things Network account (or ChirpStack)
• "MKRWAN" library (v1.1.2)

Complete Code

#include <MKRWAN.h>

LoRaModem modem;   // module Murata câblé en SPI interne
String appEui = "0080000000000001";
String appKey = "00112233445566778899AABBCCDDEEFF";

void setup {
  Serial.begin(115200);
  while (!Serial) {}
  if (!modem.begin(EU868)) {   // bande de TA carte
    Serial.println("Module KO - firmware probablement obsolete");
    while (1) {}
  }
  Serial.print("fw="); Serial.println(modem.version);
  Serial.print("DevEUI="); Serial.println(modem.deviceEUI);
  if (!modem.joinOTAA(appEui, appKey)) {
    Serial.println("Join echoue : cles, couverture, gateway ?");
    while (1) {}
  }
  modem.minPollInterval(60);   // le firmware impose >= 1 msg / 2 min
  Serial.println("JOIN OK");
}

void loop { delay(1000); }

Expected Verification

The monitor displays the AT firmware version, the DevEUI (to be registered on TTN), and then "JOIN OK". The server shows the corresponding OTAA join.

Common Errors

• "Failed to start module": the module firmware is too old, see the firmware update tutorial.
• joinOTAA sometimes reports a false error (known bug, issue #139): check the server-side status before doubting the hardware.
• Wrong band (US915 configured on an EU868 board): no gateway is heard.